Voltage regulators control or adjust an incoming source of electrical potential to meet specific requirements of an electronic device. Voltage regulators increase or decrease the voltage provided by the source, and provide a substantially constant voltage to the device despite variations in current dissipated by the device or variations in the value of the incoming source voltage. A portion of the power supplied to an input of a voltage regulator is dissipated by the regulator, and thus not provided at the output of the voltage regulator. The amount of power provided by voltage regulators, expressed as a percentage fraction of the power received, is referred to as the voltage conversion efficiency of the voltage regulator.
Switched capacitor voltage regulator designs utilize flying capacitor techniques. In this scheme, a capacitor is electronically switched between input and output ports to transfer charge that the capacitor received from the input port to the output port. Output voltage regulation is accomplished by controlling the switching rate of the flying capacitor and the ratio between the value of the flying capacitor and output capacitance. In commercially available designs, a single capacitive element is used to implement the flying capacitor function. Since only a single capacitive element is used, no power conversion is possible with this scheme since there is no change in the value of the flying capacitor, and thus the input port current remains equal to or greater than the output port current. Hence, the efficiency of switched capacitor voltage regulators is approximately equal to that of linear series voltage regulators. One advantage of switched capacitor voltage regulators is voltage inversion capabilities, which provide a negative output voltage from a positive voltage source.